'The final cost for policing in the aftermath of the nerve agent attack in Salisbury is expected to exceed £10 million for Wiltshire Police alone, the force has revealed.

In an unusual disclosure, the police and crime commissioner for Wiltshire and Swindon said he “fully expects” all costs to be reimbursed by the government, following the “unimaginable” events from earlier this year.

However, the total figure for all forces could be far higher when costs incurred by the Metropolitan Police, whose counterterror officers are leading the investigation, is ultimately taken into account.

Wiltshire Police were forced to meet “extraordinary demand”, commissioner Angus Macpherson said, after a former Russian spy, Sergei Skripal, and his daughter Yulia were attacked with novichok in March.

Russia is suspected by the government of being behind the poisoning despite Moscow’s vehement denials. The incident later claimed the life of a British national, Dawn Sturgess, after the 44-year-old, who lived in the nearby town of Amesbury, picked up a discarded perfume bottle containing the nerve agent.

More than £7 million of Wiltshire Police’s bill will cover the cost of drafting in extra officers from 40 other forces, Mr Macpherson said in a statement, with more than £1.3 million being spent on overtime for local officers and staff.'